Weak Motor? (My experience with upgraded guns, part 2)
So, I've been having terrific luck with upgraded guns lately. Really wish I could just go back to stock. (Learn from me kids! Don't upgrade!)
After having lots of trouble with my SAW, I got rid of it and ended up with an m4 that used to be a marui (now It's pretty much all aftermarket parts). This shot for a while, although the rof seemed to be a little slow. Then it stopped firing.
I took it all apart. The gearbox is fine. The motor runs outside of the gun but seems to be very, very weak (ICS 3000 motor I believe). Put into the gun, it won't turn over, regardless of how it is adjusted.
Can a motor lose significant amounts of power without totally "burning out"? Is there another explanation for this? The battery seems to be fine and there is a fairly strong spring installed.
If it is actually shooting 380-390 then the ICS motor should turn it without a problem. My MP5 chronoed 380, stock ICS internals with Ics turbo 3000 and it's running roughly 850 rpm on an 8.4v.
Also it will say ICS Turbo 3000 on the label.
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"A prisoner of war is a man who tries to kill you, fails, and then asks you not to shoot him."- Winston Churchill
Try using another battery, and see if maybe the current one you have isnt messed up. If that doesnt seem to be the remedy then you either have a locked up gearbox. Try turning the pinion gear manually (with your hand). Since the motor has a magnetic effect it will draw what ever metal parts are around it, including small screws. Its possible that one may have gotten into your motor and if so could damage the internals of it. I doubt thats the cause but it can happen (from experience...). If the motor is old then it could be getting weaker, but it takes alot of shooting to do that. Theres brushes on the motor that get worn down the motor it is used. Check to see if they are worn out. If you have another motor try using that and see if the mechbox turns. All in all you may have to crack the mechbox to see if it could be an internal problem.
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Official Airsoft Tech of Montgomeryville Army Navy.
I assume you checked already but is your piston head still on the piston? My M4 had a similar problem and it was the piston head which would let the motor spin but allowed no response from the rest of the gearbox. You have to take the piston out of the cylinder to check.
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"A prisoner of war is a man who tries to kill you, fails, and then asks you not to shoot him."- Winston Churchill
The piston is ok, that was the first thing I checked because the last time I dealt with a broken gun the piston was stripped. The motor makes a sound like it is trying to spin but can't when it's in the gun.
Hey you should use bigger wires on the thing throught out the whole gear box. I was having problems with my racing mower with the milled heads the starter did not have enought power to turn the engine over it would hit the compression stroke and just bounce back. turns out the wires were to small of a gauge to bring the amperage to the motor switched them out for some thicker gauge wires and it spun the motor over pretty fast!
I'm not so sure it's the wires because it shot fine initially (although the gearbox seemed like it took a while to turn over on a 9.6v), and then suddenly ceased to fire without any sort of decline in performance.
Ok, so I tried a new battery, which helped. The motor spun much more strongly out of the gun, and managed to compress the spring. Then it stopped, and I had to take the gearbox apart to decompress it. Needless to say, parts got everywhere so It looks like I'm going to need to re-build the whole thing when I have time. Good news is nothing should be broken!
Usually you can decompress the spring by lifting the anti-reversal latch (through the hole in the mechbox where the motor shaft goes.)
Not that it helps you much now.
Watch the www.mechbox.com videos and maybe you can get it put back together yourself. Just take your time.
I've been on mechbox.com a lot and I rebuilt a SAW gearbox pretty much from scratch so I should be OK. Off school for thanksgiving break so I'll clean the grease off of everything and re-construct it tomorrow (ideally!).
Old Man, your warhouse setup looks ill, I'm definitely going to have to get some friends up your way to try it out.
Ok, I got the gearbox cleaned up. Whoever did the upgrading did a terrible job; nothing sealed and there was grease everywhere. People need to take more pride in their work. All the gearbox parts seem to be in good condition and are now all lightly greased and the cylinder has a good seal (yay).
Motor still running outside the gearbox fine, then inside the gearbox it won't give any kind of response.
I thought it might be the trigger switch (or whatever the proper name is for the electrical business around the trigger), but if that was the case the motor wouldn't run outside of the gun. I'm stumped.
Easiest thing to do I guess would be to replace the motor and see if that helps.
The gears do spin. I specifically checked that because I don't have extra shims right now and I wasn't positive on how good the shimming was. It's not fantastic but it should be adequate. I'll look into putting thicker wires in or a different motor, but I'm not sure yet how much I'm willing to put into this gun.
If wires were the problem wouldn't it never have shot? (It did shoot, then stopped.)
they could be bad or something and the motor probably got weak, new wires are cheep and its easy to do if you know how to solder/ re wire stuff. With this kind of stuff its kinda of a crap shoot.
I'm not sure I'm ready to try re-wiring. If I was to replace the motor, would my best bet be to go back to an eg700 or eg1000, or to replace it with some sort of upgraded motor?
If you aren't comfortable with the intimate workings of the mechbox, stay away from attempting to rewire.
If the wires aren't capable of handling the current the motor is drawing from the battery, the fuse would likely blow.
If you have another motor in a different AEG, swap that in and see if it helps.
You said the gun shot for a while then stopped. Are we talking about working for a few games, or just a few shots?
We're talking about a half magazine of getting the hop set right and getting used to how the gun shoots.
The fuse is fine, and I'm plenty comfortable inside a gearbox, but I'm not so hot at soldering. I've done it before, but I'd rather stay away from it if I can. I have a UTG mp5 I can cannibalize a motor from, but I'm pretty sure mp5s use a shorter motor than m4s?
If you aren't comfortable with the intimate workings of the mechbox, stay away from attempting to rewire. If the wires aren't capable of handling the current the motor is drawing from the battery, the fuse would likely blow.
If you have another motor in a different AEG, swap that in and see if it helps.
You said the gun shot for a while then stopped. Are we talking about working for a few games, or just a few shots?
I agree with Palafoxx. Unless the fuse burns out (or the wiring is overheating and smoking) it is probably not the wiring that is at fault.
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Swapped motors, hooked up a battery, and....nothing. Hmm. Well I guess that rules out the motor. I've been inside the box a couple times and nothing really stands out as being out of place or wrong. What should I be looking for?
Shimmed too tight, although you already said that doesn't seem to be the problem.
How about spring guide? Did you replace the stock one with a ball bearing guide?
I had an Echo1 M4 that wouldn't turn over once I swapped the spring guide. The aftermarket guides compress the spring moreso than the factory guides due to the addition of the ball bearing.
You also mention in your first post that you have a fairly "Strong Spring" installed. Try the stock spring. Maybe you've just got too much spring to compress?
